The statements in this section merely provide background information related to the present invention and may not constitute prior art.
Hospitals and doctor's offices, food preparation areas, and public areas are breeding grounds for dangerous bacteria and viruses. According to the Center for Disease Control (CDC), in American hospitals alone, healthcare-associated infections (also called nonsocomial infections) account for an estimated 1.7 million infections and 99,000 associated deaths each year. A recent study reports that the annual direct medical costs from these healthcare-associated infections to U.S. hospitals ranges from $35.7 billion to $45 billion. Along with these direct costs come indirect costs, which can be just as damaging as loss of money. Examples of some indirect costs are lost wages, diminished worker productivity on the job, short and long term morbidity, mortality, income lost by family members, forgone leisure time, and time spent by family/friends for hospital visits, travel costs, and home care. Millions of other people are infected by food poisoning brought on by food being cross-contaminated and prepared in unclean areas. The cost for these food borne illnesses are about $35 billion, consisting of health care costs and lost productivity.
Bacteria and viruses are able to live and grow in a wide spectrum of conditions. One thing is key, however, and that is that the bacteria or viruses must be introduced to the location. They are not able to spontaneously appear. Many patients who go to healthcare facilities go because they are ill, and certain bacteria or viruses cause the illnesses. During their check-ups or treatments, the patients introduce the bacteria and viruses to the rooms. Infections occur when health care rooms do not get sterilized thoroughly. Bacteria and viruses will continue to live, and possibly even multiply in an area thought to be clean. A patient reports to the room during their visit, and the bacteria or virus may infect the patient. Patients have a greater risk of infection because they are usually in a weakened health position due to the illness or injury that brought them to the health care facility in the first place.
Wiping down the surfaces and floors of healthcare rooms with disinfectants has been the primary way to sterilize the rooms. The scope of cleaning is limited to the time and effort put in by the person or people cleaning the room. Additionally, in recent years, some bacteria and viruses have developed resistances to the standard disinfectants. Therefore, there is need in the art to provide a coating on the surfaces and floors of healthcare rooms to provide for continuous, uniform sterilization, thus resulting in lower levels of bacteria and viruses resulting in fewer cases of nonsocomial infections.
Another technique used to clean healthcare rooms is with the use of gases such as formaldehyde or chlorine dioxide. The gases are pumped into the healthcare facilities for a set period of time and the gases kill the bacteria and viruses. Along with being questioningly effective, the gases used are extremely toxic to people. For example, some scientists believe that chlorine dioxide may actually leave crystals behind which would aid the regeneration of mold it is intended to kill. Additionally, Chlorine dioxide is a severe respiratory and eye irritant in humans. Therefore, to use the gases to sterilize (i.e., fumigate), the healthcare facilities, as well as the surrounding areas, must be shut down and everyone must be evacuated for a certain amount of time. The gases must be given time to work, and then to disperse enough for it to be safe for people to reenter the facilities. The closure of the healthcare facilities creates difficulties where people are forced to obtain treatment at unfamiliar or inconvenient places.
Direct ultraviolet (UV) sterilization has shown to be an effective way of sterilizing healthcare rooms. For example, U.S. Pat. No. 5,920,075 to Whitehead discloses the use of ultraviolet radiation, from an ultraviolet light source, in a range sufficient to eradicate germs, bacteria, viruses, and other pathogens and microorganisms. U.S. Pat. No. 6,656,424 to Deal (the “424 patent”) teaches the use of a mobile ultraviolet generator, which first scans the room to make sure everyone has evacuated, and then generates UV-C radiation to sterilize the room. Direct UV sterilization does have a similar problem to gas sterilization, however. UV rays are harmful to humans, especially in higher amounts of exposure. UV rays can cause sunburn, skin cancer, and aging of the skin, as well as cataracts and pinguecula in the eyes. Therefore, direct UV sterilization, as described in the '424 patent, can only occur when no humans are in a room.
The present invention addresses needs in the art improvements in the self-sterilization of hospital surfaces from ambient or direct lighting stimulation, food preparation surfaces, public or private bathrooms, dining tables, and public surfaces.